Abstract
Colour vision starts in the retina where light is absorbed in three different cone classes, sensitive to long-, medium-, and short-wavelength light. The cone signals then feed into three different post-receptoral channels, a luminance channel and two cone-opponent chromatic -channels (Derrington, Krauskopf & Lennie, 1984). These two cone-opponent chromatic channels do not correspond to perceptually salient colour mechanisms (unipolar red, green, yellow, blue), suggesting that the two sub-cortical chromatic channels are recombined in visual cortex into orderly hue maps consistent with our fMRI experiments.
Our behavioural results show that hue mechanisms are almost invariant with age and ambient illumination. Variability in unique hue settings across observers is only twice as large as within observer variability.
All these results taken together suggest that the human visual system is able to compensate for retinal (peripheral) signal changes by adjusting the relative cone weightings of the cortical colour mechanisms. The mechanism underlying this hue compensation is still poorly understood, but it is likely that it utilises invariant sources in our visual environment.
Meeting abstract presented at the 2016 OSA Fall Vision Meeting